Hostname: page-component-586b7cd67f-r5fsc Total loading time: 0 Render date: 2024-11-25T17:41:31.701Z Has data issue: false hasContentIssue false

Stress, Microstructure and Temperature Stability of Reactive Sputter Deposited Ta(N) Thin Films

Published online by Cambridge University Press:  10 February 2011

K. D. Leedy
Affiliation:
Air Force Research Laboratory, Sensors Directorate, Wright-Patterson AFB, OH 45433, [email protected]
M. J. O'Keefe
Affiliation:
University of Missouri-Rolla, Dept. of Metallurgical Engineering, Rolla, MO 65409
J. T. Grant
Affiliation:
Research Institute, University of Dayton, Dayton, OH 45469
Get access

Abstract

Interest in tantalum nitride thin films for use as diffusion barriers in Cu-based microelectronic interconnects merits the study of tantalum nitride thin film properties as a function of deposition conditions and elevated temperature exposure. In this investigation, the influence of nitrogen content and post deposition annealing on the stress, microstructure and resistivity of Ta(N) films was analyzed. Ta(N) thin films were deposited by reactive dc magnetron sputtering of a Ta target in Ar/N2 gas mixtures. With an increasing N2 to Ar flow ratio, the as-deposited crystal structure of the films changed from ß-Ta to bcc Ta with N in solid solution to TaN0.1 to Ta2N and finally to TaN. The as-deposited Ta(N) stress, grain size and resistivity of the films were found to be strongly dependent on the phase(s) present. Films with less than 20 at. % nitrogen concentration displayed large compressive stress increases during 650°C anneals in flowing N2. Phase transformations to Ta2N occurred after 650°C anneals in films with nitrogen concentrations from ∼ 15 to 25 at. %. Microstructural characterization using transmission electron microscopy and x-ray diffraction, and chemical analysis by x-ray photoelectron spectroscopy and Auger electron spectroscopy of the Ta(N) films were used to identify the as-deposited and transformed phases.

Type
Research Article
Copyright
Copyright © Materials Research Society 2000

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Wong, S. S., Ryu, C., Lee, H. and Kwon, K.-W. in Advanced Interconnects and Contact Materials and Processes for Future Integrated Circuits, edited by Murarka, S. P., Fraser, D. B., Eizenberg, M., Tung, R., Madar, R. (Mater. Res. Soc. Proc. 514, Wa rrendale, PA, 1998) pp. 7581.Google Scholar
2. Chin, B., Solid State Technol. 41(7), 141 (1998).Google Scholar
3. Sun, X., Kolawa, E., Chen, J.-S., Reid, J. S. and Nicolet, M.-A., Thin Solid Films 236, 347 (1993).Google Scholar
4. Stavrev, M., Fischer, D., Wenzel, C., Drescher, K. and Mattern, N., Thin Solid Films 307, 79 (1997).Google Scholar
5. Min, K.-H., Chun, K.-C. and Kim, K.-B., J. Vac. Sci. Technol. B 14(5), 3263 (1999).Google Scholar
6. Holloway, K., Fryer, P. M., Cabral, C., Harper, J. M. E., Bailey, P. J. and Kelleher, K. H., J. Appl. Phys. 71(11), 5433 (1992).Google Scholar
7. Takeyama, M., Noya, A., Sase, T. and Ohta, A., J. Vac. Sci. Technol. B 14(2), 674 (1996).Google Scholar
8. Venkatraman, R. in Advanced Interconnects and Contact Materials and Processes for Future Integrated Circuits, edited by Murarka, S. P., Fraser, D. B., Eizenberg, M., Tung, R., Madar, R. (Mater. Res. Soc. Proc. 514, Wa rrendale, PA, 1998) pp. 4152.Google Scholar
9. Kim, N. P., Coates, K. L., Kunze, G. G., Chien, C.-P. and Tanielian, M. H., IMAPS Conf, Oct 97, Philadelphia, PA.Google Scholar
10. Cabral, C., Clevenger, L. A. and Schad, R. G., J. Vac. Sci. Technol. B 12(4), 2818 (1994).Google Scholar
11. Clevenger, L. A., Mutscheller, A., Harper, J. M. E., Cabral, C. and Barmak, K., J. Appl. Phys. 72(10), 4918 (1992).Google Scholar
12. Radhakrishnan, K., Ing, N. G. and Gopalakrishnan, R., Mat. Sci. Eng. B 57, 224 (1999).Google Scholar
13. Saha, R. and Barnard, J. A., J. Crystal Growth 174, 495 (1997).Google Scholar
14. Catania, P., Roy, R. A. and Cuomo, J. J., J. Appl. Phys. 74(2), 1008 (1993).Google Scholar